Complex plants, which comprise a plurality of cooperating, differing devices, are nowadays preferably controlled using PC-based control solutions with respect to a control of movements (hereinafter also referred to as motion world). The devices of such a plant which are to be jointly controlled can e.g. be CNC systems (CNC: Computer Numeric Control), RC systems (RC: Robot Controller) and/or PLC systems (PLC: Programmable Logic Control; as well as SPC: Stored Programmable Control), PLC and Soft PLC systems being treated in the same way (Soft PLC/Soft SPC: software-constructed PLC/SPC).
In complex plant concepts, such as e.g. in laser plant technology, it is necessary to have numerous coordination possibilities between robots, clamping and holding devices, laser and bar controls. Thus, e.g. the geometry stations of leading car manufacturers are coordinated by means of an internal protocol of an ASCII interface using external personal computers (PC), in order to obtain an identical time behavior or response of the robot world (RC core), CNC clamping technology and laser technology. It is necessary for the individual time responses of the different motion worlds (RC, CNC, PLC) to be sent in a specially defined ASCII data file via a suitable protocol, such as TCP/IP, to a coordination PC, which corrects the said three motion worlds with regards to their time response or behavior and by means of the ASCII file sends same back to the different controls. The structure and sequence of such control methods and apparatuses are complex and correspondingly inflexible.
It is known to provide a plurality of instances (CPUs), whereof one is a centralized instance and the other decentralized instances. Each instance has its own clock generation unit. The units of the decentralized instances are synchronized by a synchronization clock of the centralized instance, i.e. the decentralized instances cannot independently generate their operational sequences corresponding to an autonomous clock, but the given clock of a decentralized instance is determined by the synchronization emanating from the centralized instance and the timing of each decentralized instance is controlled by the synchronization clock of the centralized instance. Thus, the processing clock of the individual control devices is directly synchronized and determined by the synchronizing signal of the centralized unit, so that the former can no longer operate with independent timing.
The problem of the invention is to avoid the aforementioned disadvantages by proposing a simplified, more flexible coordination and motion planning, particularly in the case of complex plants of the aforementioned type.